Pneumatic piano.



No. 702,030. Patented lune I0, |902. S. K. REYNOLDS.

PNEUMATIG PIANO.

(Application filed Nov. 15, 1900.)

(No Model.)

INVENTR THE News Firms co, mom-nwo.. wAsHwmoN. o. c,

l UNITED STATES' PATENT OFFICE.

STEPHEN K. REYNOLDS, OE NEW YORK, N. Y.

PN EU MATlC PIANO.

SPECIFICATION forming part of Letters Patent No. 702,030, dated June 10, 1902.

Application iiled November l5, 1900. Serial No. 36,555. (N0 model.)

T0 all whom t may concern.-

Be it known that l, STEPHEN K. REYNOLDS, a citizen of the United States, residing at the city of New York, in the borough of Manhattan and State of NewYork, have invented certain new and useful Improvements in Pneumatic Pianos, of which the following is a full, clear, and exact description.

This invention relates to automatic musical instruments with special reference to pianos, the object being to produce simple pneumatically-operable apparatus which may be contained within small compass and adapted to be readily attached to and detached from the keyboard of a piano and which shall not necessitate important changes, it any, in the piano itself or impair its effectiveness as a manually-operative instrument.

A further object is to imitate the action of the human iinger inloperating the keys,which I accomplish by locating the key-depressing devices directly over the keys, near the ends thereof, and causing` the same to move in a vertical direction.

. The key-depressing mechanism consists of a series of cylinders supported above the keyboard in two rows, one for the white keys and one for the black, there being a cylinder for each key and each cylinder containing an airoperative plunger, having a downwardlyprojecting stem, which rests directly upon the upper surface of its respective key. The plnngers are depressed by a pressure of air admitted to the cylinders, and since said pressure is directly transmitted to the piano-keys instead of passing through various links and levers the slightest variations in the volume of air admitted to the cylinder will produce corresponding modulations of the sound produced. I am therefore able to obtain by a simple valve arrangement a delicate control of expressiom which is a still further object of my invention.A The plungers, it should be understood, are not mechanically connected with the keys, but simply rest upon the same, being light enough. to be supported thereby in their normal elevated position. After being depressed by the air they will be returned to normal position by the same force which returns the key.

.A complete understanding of the invention may be had by reference to the accompanying drawings, in which- Figure 1 is a perspective view of one end of a piano, showing my invention applied thereto. Fig. 2 is a sectional View, enlarged, taken along line fr c of Fig. l. Fig. 3 is a detail sectional view of a portion of Fig. 2, taken along line y y. Fig. l is a sectional detail of a keyactuating device, and Fig. 5 is a modified form of a key-actuating device.

Referring to the drawings by letter, A represents a frame consisting of a flat elongated casing a and the comparatively narrow superstructure a2, preferably located in lthe middle of the frame. The bottom board a3 of the frame is somewhat longer than the keyboard and rests upon the usual spacing-blocks l) at each end of the row of keys. To hold the frame steadily in place, the blocks l) may be provided with buttons bf, adapted to pass through slots a in the projecting ends of the bottom board of the frame and then given a quarter-turn. Upon or in the bottom board of the frame are mounted two rows of cylinders C, one for the white keys and one for the black, one cylinder being placed centrally above each key and with its axis at right angles tothe key. The cylinders are closed at their upper ends and are each tted with a plunger D, which is also preferably a cylinder closed at its lower end. These plungers carry downwardly-projecting stems d, provided with heads d', of felt or soft rubber, which rest directly upon the keys. Each cylindergC is further provided with an air-inlet g and an air-outlet g and preferably with an automatic valve of suitable construction. A simple form of such valve is shown in Fig. 4 and consists of a loose ball g2, located in the transverse passage Q3 and normally occupying the position shown in full lines, the floor of said passage being slightly inclined, as shown. Passage gS connects with or is a part of the air-inlet g, so that a flow of air through said passage toward the cylinder will force the ball g? from its normal position to the position shown in dotted linkes, where, as indicated, it will close the loutlet g', located at the end of the passage. Vhen the supply of air is checked, the ball will return to normal position by gravity, opening the outlet g for IOO the free escape of the air in the cylinder and allowing the plunger' to be raised by the key without resistance. In some instances a valve may be found unnecessary, a simple outlet-valve, as indicated at g4 in Fig. 5, taking its place.

The mechanism which controls the admission of air to the cylinders is inclosed within the superstructure a2, before referred to.

K represents the source of air-supply, and 7c the pipe leading therefrom to the front panel of the piano, Where it will be provided with a flaring mouth 7c', having a lining of soft rubber or other suitable packing material. Preferably pipe 7c will be concealed Within the frame of the piano, the daring mouth Zc only being visible.

L is a pipe projecting through the back board of the superstructure a2 and having a conical end, which when frameA is in operative position will iit snugly within the mouth 7c. The inner end of pipe L connects with a chamber L', which is provided with an outer concave surface Z, having a slit or air-outlet Z'. This pipe is also provided with a valve Z3, controllable from the outside of the superstructure a' by a handle n2.

F is a frame carried by the pivoted arms F and having a convex surfacef, corresponding to and adapted to stand in parallel relation with the concave surface Z. The frame is also provided with a series of separate airtubes F2, there being as many such tubes as there are cylinders C and each tube being connected by a iiexible tube f3 with its corresponding cylinder. Theends of the tube F2 open to the slit Z. A spring]c4 tends to hold frame F in contact with orin a position closely adjacent to the chamber L, but is adapted to be readily disengaged when desired and the frame F swung outwardly clear of said chamber.

N represents the usual perforated musicsheet commonly employed in instruments of this character, and N a suitable motor for driving the same. The sheet will be drawn from roller n to roller n', passing between and in contact with the vcurved surfaces Zand f aforesaid, opening and closing communication between the chamber L and the air-passages F2,according to the arrangement of the perforations in said sheet. The unperforated portions ofthe music-sheet bar the entrance of air from chamber L to the tubes F2, While the perforations in the sheet permit the air to iiow to the respective cylinders while they are passing the open-ended tubes F2. The pressure of air passing into a cylinder forces its piston downward,and the key is depressed. If the pressure is prolonged, the Vtone is sustained correspondingly7 and the instant the source of pressure is cut olf the air escapes and permits the key to return to its normal position. By the aid of the valve Z3 the pressure admitted to the chamber can be controlled, with the result that the stroke on the keys is varied and expression in the music obtained.

Having described my invention, I claim- 1. In a pneumatically-operated keyboard instrument, the combination of an air-chamber having a perforated wall, a series of tubes opening against said perforated wall, a series of air-cylinders connected with the respective tubes and a perforated sheet adapted to pass between the ends of the tubes and the perforated wall, substantially as described.

2. In a pneumatically-operated keyboard instrument, the combination of an air-chamber having a perforated wall, a series of tubes opening against said perforated wall, a series of air-cylinders connected with the respective tubes, a pivoted frame supporting the ends of said tubes, means for 'forcing said frame toward said wall and a perforated sheet adapted to pass between the ends of the tubes and the wall, substantially as described.

In witness whereof I subscribe my signature in presence of two witnesses.

STEPHEN K. REYNOLDS.

Witnesses:

WM. A. RosENBAUM, WALDO M. CHAPIN. 

